Commit graph

339 commits

Author SHA1 Message Date
Alexander Barkov
e963b0d12f MDEV-16725 Add accessor methods for classes in item_timefunc.h 2018-11-27 14:08:03 +04:00
Alexander Barkov
4447a02cf1 MDEV-16991 Rounding vs truncation for TIME, DATETIME, TIMESTAMP 2018-11-26 08:10:47 +04:00
Alexander Barkov
21a5884081 MDEV-17776 CAST(x AS INTERVAL DAY_SECOND(N)) 2018-11-20 13:47:52 +04:00
Alexander Barkov
d2ba9edd66 MDEV-17740 Extend EXTRACT(x AS DAY*) to understand long time intervals 2018-11-17 10:14:44 +04:00
Alexander Barkov
07e4853c23 MDEV-17563 Different results using table or view when comparing values of time type
MDEV-17625 Different warnings when comparing a garbage to DATETIME vs TIME

- Splitting processes of data type conversion (to TIME/DATE,DATETIME)
  and warning generation.
  Warning are now only get collected during conversion (in an "int" variable),
  and are pushed in the very end of conversion (not in parallel).
  Warnings generated by the low level routines str_to_xxx() and number_to_xxx()
  can now be changed at the end, when TIME_FUZZY_DATES is applied,
  from "Invalid value" to "Truncated invalid value".

  Now "Illegal value" is issued only when the low level routine returned
  an error and TIME_FUZZY_DATES was not set. Otherwise, if the low level
  routine returned "false" (success), or if NULL was converted to a zero
  datetime by TIME_FUZZY_DATES, then "Truncated illegal value"
  is issued. This gives better warnings.

- Methods Type_handler::Item_get_date() and
  Type_handler::Item_func_hybrid_field_type_get_date() now only
  convert and collect warning information, but do not push warnings.

- Changing the return data type for Type_handler::Item_get_date()
  and Type_handler::Item_func_hybrid_field_type_get_date() from
  "bool" to "void". The conversion result (success vs error) can be
  checked by testing ltime->time_type. MYSQL_TIME_{NONE|ERROR}
  mean mean error, other values mean success.

- Adding new wrapper methods Type_handler::Item_get_date_with_warn() and
  Type_handler::Item_func_hybrid_field_type_get_date_with_warn()
  to do conversion followed by raising warnings, and changing
  the code to call new Type_handler::***_with_warn() methods.

- Adding a helper class Temporal::Status, a wrapper
  for MYSQL_TIME_STATUS with automatic initialization.

- Adding a helper class Temporal::Warn, to collect warnings
  but without actually raising them. Moving a part of ErrConv
  into a separate class ErrBuff, and deriving both Temporal::Warn
  and ErrConv from ErrBuff. The ErrBuff part of Temporal::Warn
  is used to collect textual representation of the input data.

- Adding a helper class Temporal::Warn_push. It's used
  to collect warning information during conversion, and
  automatically pushes warnings to the diagnostics area
  on its destructor time (in case of non-zero warning).

- Moving more code from various functions inside class Temporal.

- Adding more Temporal_hybrid constructors and
  protected Temporal methods make_from_xxx(),
  which convert and only collect warning information, but do not
  actually raise warnings.

- Now the low level functions  str_to_datetime() and str_to_time()
  always set status->warning if the return value is "true" (error).

- Now the low level functions number_to_time() and number_to_datetime()
  set the "*was_cut" argument if the return value is "true" (error).

- Adding a few DBUG_ASSERTs to make sure that str_to_xxx() and
  number_to_xxx() always set warnings on error.

- Adding new warning flags MYSQL_TIME_WARN_EDOM and MYSQL_TIME_WARN_ZERO_DATE
  for the code symmetry. Before this change there was a special
  code path for (rc==true && was_cut==0) which was treated by
  Field_temporal::store_invalid_with_warning as "zero date violation".
  Now was_cut==0 always means that there are no any error/warnings/notes
  to be raised, not matter what rc is.

- Using new Temporal_hybrid constructors in combination with
  Temporal::Warn_push inside str_to_datetime_with_warn(),
  double_to_datetime_with_warn(), int_to_datetime_with_warn(),
  Field::get_date(), Item::get_date_from_string(), and a few other places.

- Removing methods Dec_ptr::to_datetime_with_warn(),
  Year::to_time_with_warn(), my_decimal::to_datetime_with_warn(),
  Dec_ptr::to_datetime_with_warn().
  Fixing Sec6::to_time() and Sec6::to_datetime() to
  convert and only collect warnings, without raising warnings.
  Now warning raising functionality resides in Temporal::Warn_push.

- Adding classes Longlong_hybrid_null and Double_null, to
  return both value and the "IS NULL" flag. Adding methods
  Item::to_double_null(), to_longlong_hybrid_null(),
  Item_func_hybrid_field_type::to_longlong_hybrid_null_op(),
  Item_func_hybrid_field_type::to_double_null_op().
  Removing separate classes VInt and VInt_op, as they
  have been replaced by a single class Longlong_hybrid_null.

- Adding a helper method Temporal::type_name_by_timestamp_type(),
  moving a part of make_truncated_value_warning() into it,
  and reusing in Temporal::Warn::push_conversion_warnings().

- Removing Item::make_zero_date() and
  Item_func_hybrid_field_type::make_zero_mysql_time().
  They provided duplicate functionality.
  Now this code resides in Temporal::make_fuzzy_date().
  The latter is now called for all Item types when data type
  conversion (to DATE/TIME/DATETIME) is involved, including
  Item_field and Item_direct_view_ref.
  This fixes MDEV-17563: Item_direct_view_ref now correctly converts
  NULL to a zero date when TIME_FUZZY_DATES says so.
2018-11-08 09:31:46 +04:00
Alexander Barkov
f7179c4432 MDEV-17460 Move the code from Item_extract::val_int() to a new class Extract_source 2018-10-16 11:14:39 +04:00
Alexander Barkov
22e75434e7 MDEV-17434 EXTRACT(DAY FROM negative_time) returns wrong result 2018-10-15 17:46:25 +04:00
Alexander Barkov
b639fe2be1 MDEV-17351 Wrong results for GREATEST,TIMESTAMP,ADDTIME with an out-of-range TIME-alike argument
Problems:

Functions LEAST() and GREATEST() in TIME context, as well as functions
TIMESTAMP(a,b) and ADDTIME(a,b), returned confusing results when the
input TIME-alike value in a number or in a string was out of the TIME
supported range.

In case of TIMESTAMP(a,b) and ADDTIME(a,b), the second argument
value could get extra unexpected digits. For example, in:
    ADDTIME('2001-01-01 00:00:00', 10000000)  or
    ADDTIME('2001-01-01 00:00:00', '1000:00:00')
the second argument was converted to '838:59:59.999999'
with six fractional digits, which contradicted "decimals"
previously set to 0 in fix_length_and_dec().
These unexpected fractional digits led to confusing function results.

Changes:
1. GREATEST(), LEAST()

   - fixing Item_func_min_max::get_time_native()
   to respect "decimals" set by fix_length_and_dec().
   If a value of some numeric or string time-alike argument
   goes outside of the TIME range and gets limited to '838:59:59.999999',
   it's now right-truncated to the correct fractional precision.

   - fixing, Type_handler_temporal_result::Item_func_min_max_fix_attributes()
   to take into account arguments' time_precision() or datetime_precision(),
   rather than rely on "decimals" calculated by the generic implementation
   in Type_handler::Item_func_min_max_fix_attributes(). This makes
   GREATEST() and LEAST() return better data types, with the same
   fractional precision with what TIMESTAMP(a,b) and ADDTIME(a,b) return
   for the same arguments, and with DATE(a) and TIMESTAMP(a).

2. Item_func_add_time and Item_func_timestamp

   It was semantically wrong to apply the limit of the TIME data type
   to the argument "b", which plays the role of "INTERVAL DAY TO SECOND" here.
   Changing the code to fetch the argument "b" as INTERVAL rather than as TIME.

   The low level routine calc_time_diff() now gets the interval
   value without limiting to '838:59:59.999999', so in these examples:
     ADDTIME('2001-01-01 00:00:00', 10000000)
     ADDTIME('2001-01-01 00:00:00', '1000:00:00')
   calc_time_diff() gets '1000:00:00' as is.  The SQL function result
   now gets limited to the supported result data type range
   (datetime or time) inside calc_time_diff(), which now calculates
   the return value using the real fractional digits that
   came directly from the arguments (without the effect of limiting
   to the TIME range), so the result does not have any unexpected
   fractional digits any more.

   Detailed changes in TIMESTAMP() and ADDTIME():

   - Adding a new class Interval_DDhhmmssff. It's similar to Time, but:
     * does not try to parse datetime format, as it's not needed for
       functions TIMESTAMP() and ADDTIME().
     * does not cut values to '838:59:59.999999'

     The maximum supported Interval_DDhhmmssff's hard limit is
     'UINT_MAX32:59:59.999999'. The maximum used soft limit is:
     - '87649415:59:59.999999'   (in 'hh:mm:ss.ff' format)
     - '3652058 23:59:59.999999' (in 'DD hh:mm:ss.ff' format)
     which is a difference between:
     - TIMESTAMP'0001-01-01 00:00:00' and
     - TIMESTAMP'9999-12-31 23:59:59.999999'
     (the minimum datetime that supports arithmetic, and the
     maximum possible datetime value).

   - Fixing get_date() methods in the classes related to functions
     ADDTIME(a,b) and TIMESTAMP(a,b) to use the new class Interval_DDhhmmssff
     for fetching data from the second argument, instead of get_date().

   - Fixing fix_length_and_dec() methods in the classes related
     to functions ADDTIME(a,b) and TIMESTAMP(a,b) to use
     Interval_DDhhmmssff::fsp(item) instead of item->time_precision()
     to get the fractional precision of the second argument correctly.

   - Splitting the low level function str_to_time() into smaller pieces
     to reuse the code. Adding a new function str_to_DDhhmmssff(), to
     parse "INTERVAL DAY TO SECOND" values.

   After these changes, functions TIMESTAMP() and ADDTIME()
   return much more predictable results, in terms of fractional
   digits, and in terms of the overall result.

   The full ranges of DATETIME and TIME values are now covered by TIMESTAMP()
   and ADDTIME(), so the following can now be calculated:

    SELECT ADDTIME(TIMESTAMP'0001-01-01 00:00:00', '87649415:59:59.999999');
    -> '9999-12-31 23:59:59.999999'

    SELECT TIMESTAMP(DATE'0001-01-01', '87649415:59:59.999999')
    -> '9999-12-31 23:59:59.999999'

    SELECT ADDTIME(TIME'-838:59:59.999999', '1677:59:59.999998');
    -> '838:59:59.999999'
2018-10-08 13:38:01 +04:00
Alexander Barkov
ad8e02ac45 MDEV-17317 Add THD* parameter into Item::get_date() and stricter data type control to "fuzzydate" 2018-09-28 14:01:17 +04:00
Alexander Barkov
c7115428ed MDEV-16881 Remove Item::get_temporal_with_sql_mode() and val_xxx_from_date() 2018-08-02 15:36:13 +04:00
Alexander Barkov
54fc47960d MDEV-16874 Implement class Item_handled_func 2018-08-01 16:15:16 +04:00
Alexander Barkov
b1ae4e7e15 MDEV-16864 Implement class Item_func_timestamp 2018-07-31 16:58:02 +04:00
Alexander Barkov
28ff7e89c6 MDEV-16852 Get rid of Item_temporal_hybrid_func::fix_temporal_type()
- Implementing the task according to the MDEV description.
- Adding a helper class Sec6_add to share the code in type-specific
  branches in Item_func_add_time::get_date().
2018-07-30 20:40:48 +04:00
Oleksandr Byelkin
083279f783 Merge commit '6b8802e8dd5467556a024d807a1df23940b00895' into bb-10.3-fix_len_dec 2018-06-19 14:51:50 +02:00
Oleksandr Byelkin
6b8802e8dd MDEV-11071: Assertion `thd->transaction.stmt.is_empty()' failed in Locked_tables_list::unlock_locked_table
fix_length_and_dec now return result (error/OK)
2018-06-15 10:31:30 +02:00
Alexander Barkov
c346029958 MDEV-15702 Remove the use of STRING_ITEM from Item_func_date_format::fix_length_and_dec()
Implementing the task according to the description.
Additionally, implementing Item_func_date_format::check_arguments().
2018-03-28 11:26:02 +04:00
Sergei Golubchik
f3088112cb MDEV-14645: AS OF TIMESTAMP is misused as TRX_ID
Remove 1668efb722 that introduced a special magic
behavior for UNIX_TIMESTAMP() in the AS OF context
2018-02-24 00:50:58 +01:00
Marko Mäkelä
b006d2ead4 Merge bb-10.2-ext into 10.3 2018-02-15 10:22:03 +02:00
Alexander Barkov
95d075a0e5 MDEV-15293 CAST(AS TIME) returns bad results for LAST_VALUE(),NAME_CONST(),SP variable 2018-02-13 20:37:31 +04:00
Vladislav Vaintroub
6c279ad6a7 MDEV-15091 : Windows, 64bit: reenable and fix warning C4267 (conversion from 'size_t' to 'type', possible loss of data)
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.

This fix excludes rocksdb, spider,spider, sphinx and connect for now.
2018-02-06 12:55:58 +00:00
Aleksey Midenkov
1668efb722 MDEV-14645: AS OF TIMESTAMP is misused as TRX_ID [fixes #396] 2017-12-14 18:14:21 +03:00
Marko Mäkelä
7cb3520c06 Merge bb-10.2-ext into 10.3 2017-11-30 08:16:37 +02:00
Michael Widenius
166056f744 Remove not used mem_root argument from build_clone(), get_copy() and get_item_copy()
TODO:
- Make get_thd_memroot() inline
  - To do this, we need to reduce dependence of include files, especially
    so that sql_class.h is not depending in item.h
2017-11-23 09:49:45 +02:00
Alexander Barkov
071aece907 MDEV-14376 Explicit CAST(CHAR(N)) erroneously escalates warnings to errors in STRICT_ALL_TABLES 2017-11-13 21:58:00 +04:00
Alexander Barkov
003cb2f424 Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext 2017-10-30 16:42:46 +04:00
Sergei Golubchik
e0a1c745ec Merge branch '10.1' into 10.2 2017-10-24 14:53:18 +02:00
Sergei Golubchik
9d2e2d7533 Merge branch '10.0' into 10.1 2017-10-22 13:03:41 +02:00
Sergei Golubchik
da4503e956 Merge branch '5.5' into 10.0 2017-10-18 15:14:39 +02:00
Alexander Barkov
e30b6a983f MDEV-11819 NO_ZERO_IN_DATE: Incorrect generated column value 2017-10-06 18:23:40 +04:00
Alexander Barkov
64bfad6307 Fixing Item_func_hybrid_field_type::date_op(,uint) to date_op(,ulonglong)
Fixing the data type for the "fuzzydate" parameter to
Item_func_hybrid_field_type::date_op() from uint to ulonglong,
for consistency with Item::get_date().
2017-10-03 13:27:52 +04:00
Alexander Barkov
6857cb57fe MDEV-13967 Parameter data type control for Item_long_func
- Implementing stricter data type control for Item_long_func descendants
- Cleanup: renaming Type_handler::can_return_str_ascii() to can_return_text()
  (a better name).
2017-10-01 00:30:58 +04:00
Alexander Barkov
aa582dedcb MDEV-13966 Parameter data type control for Item_temporal_func 2017-09-30 11:17:19 +04:00
Alexander Barkov
ca38b93e35 MDEV-13965 Parameter data type control for Item_longlong_func 2017-09-29 22:44:07 +04:00
Sergei Golubchik
80b9ce3593 MDEV-11553 Can't restore a PERSISTENT column that uses DATE_FORMAT()
3-argument form of DATE_FORMAT
2017-09-23 20:22:46 +02:00
Sergei Golubchik
1320ad5b92 Merge branch '10.2' into bb-10.2-ext 2017-09-23 20:22:30 +02:00
Sergei Golubchik
bc4409ab4e MDEV-13868 cannot insert 1288481126 in a timestamp column in Europe/Moscow
make insert NULL into a timestamp mark the field as having an
explicit value. So that the field won't be assigned the value
again in TABLE::update_default_field()

make Item_func_now_local::save_in_field(timestamp_field) not to go
through MYSQL_TIME - this conversion is lossy around DST change times.
This fixes inserting a default value into a timestamp field.
2017-09-22 13:58:00 +02:00
Marko Mäkelä
fc3b1a7d2f Merge 10.2 into bb-10.2-ext 2017-09-20 17:47:49 +03:00
Sergei Golubchik
8b1f145c82 cleanup
Item_func_format::print() was redundant
and other changes
2017-09-18 10:12:23 +02:00
Sergei Golubchik
c4dc2b877a bugfix: TIME_FORMAT() should be ok in stored generated columns 2017-09-18 10:12:23 +02:00
Alexander Barkov
109bc47084 Fixing a few data type related problems: MDEV-12875, MDEV-12886, MDEV-12916
This is a joint patch fixing the following problems:

MDEV-12875 Wrong VIEW column data type for COALESCE(int_column)
MDEV-12886 Different default for INT and BIGINT column in a VIEW for a SELECT with ROLLUP
MDEV-12916 Wrong column data type for an INT field of a cursor-anchored ROW variable

All above problem happened because the global function ::create_tmp_field()
called the top-level Item::create_tmp_field(), which made some tranformation
for INT-result data types. For example, INT(11) became BIGINT(11), because 11
is a corner case and it's not known if it fits or does not fit into INT range,
so Item::create_tmp_field() converted it to BIGINT(11) for safety.

The main idea of this patch is to avoid such tranformations.

1. Fixing Item::create_tmp_field() not to have a special case for INT_RESULT.

   Item::create_tmp_field() is changed not to have a special case
   for INT_RESULT (which earlier made a decision based on Item's max_length).
   It now calls tmp_table_field_from_field_type() for INT_RESULT,
   therefore preserves the original data type (e.g. INT, YEAR) without
   conversion to BIGINT.

   This change is valid, because a number of recent fixes
   (e.g. in Item_func_int, Item_hybrid_func, Item_int, Item_splocal)
   guarantee that item->type_handler() now properly returns
   type_handler_long vs type_handler_longlong. So no adjustment by length
   is needed any more for Items returning INT_RESULT.

   After this change, Item::create_tmp_field() calls
   tmp_table_field_from_field_type() for all XXX_RESULT, except REAL_RESULT.

2. Fixing Item::create_tmp_field() not to have a special case for REAL_RESULT.

   Note, the reason for a special case for REAL_RESULT is to have a special
   constructor for Field_double(), forcing Field_real::not_fixed to be set
   to true.

   Taking into account that only Item_sum descendants actually need a special
   constructor call Field_double(not_fixed=true), not too loose precision
   when mixing individual rows to the aggregate result:
   - renaming Item::create_tmp_field() to Item_sum::create_tmp_field().
   - changing Item::create_tmp_field() just to call
     tmp_table_field_from_field_type() for all XXX_RESULT types.

   A special case for REAL_RESULT in Item::create_tmp_field() is now gone.
   Item::create_tmp_field() is now symmetric for all XXX_RESULT types,
   and now just calls tmp_table_field_from_field_type().

3. Fixing Item_func::create_field_for_create_select() not to have
   a special case for STRING_RESULT.

   After changes #1 and #2, the code in
   Item_func::create_field_for_create_select(), testing result_type(),
   becomes useless, because: now Item::create_tmp_field() and
   tmp_table_field_from_field_type() do exactly the same thing for all
   XXX_RESULT types for Item_func descendants:
   a. It calls tmp_table_field_from_field_type for STRING_RESULT directly.
   b. For other XXX_RESULT, it goes through Item::create_tmp_field(),
      which calls the global function ::create_tmp_field(),
      which calls item->create_tmp_field() for FUNC_ITEM,
      which calls tmp_table_field_from_field_type() again.

   So removing the virtual implementation of
   Item_func::create_field_for_create_select().
   The inherited Item::create_field_for_create_select() now perfectly
   does the job, as it also calls tmp_table_field_from_field_type()
   for FUNC_ITEM, independently from XXX_RESULT type.

4. Taking into account #1 and #2, as well as some recent changes,
   removing virtual implementations:
   - Item_hybrid_func::create_tmp_field()
   - Item_hybrid_func::create_field_for_create_select()
   - Item_int_func::create_tmp_field()
   - Item_int_func::create_field_for_create_select()
   - Item_temporal_func::create_field_for_create_select()
   The derived versions from Item now perfectly work.

5. Moving a piece of code from create_tmp_field_from_item()
   to a new function create_tmp_field_from_item_finalize(),
   to reuse it in two places (see #6).

6. Changing the code responsible for BIT->INT/BIGIN tranformation
   (which is called for the cases when the created table, e.g. HEAP,
    does not fully support BIT) not to call create_tmp_field_from_item(),
   because the latter now calls tmp_table_field_from_field_type() instead
   of create_tmp_field() and thefore cannot do BIT transformation.
   So rewriting this code using a sequence of these calls:
   - item->type_handler_long_or_longlong()
   - handler->make_and_init_table_field()
   - create_tmp_field_from_item_finalize()

7. Miscelaneous changes:
   - Moving type_handler_long_or_longlong() from "protected" to "public",
     as it's now needed in the global function create_tmp_field().

8. The above changes fixed MDEV-12875, MDEV-12886, MDEV-12916.
   So adding tests for these bugs.
2017-05-25 15:15:39 +04:00
Alexander Barkov
d9304914be Fixing a few problems with data type and metadata for INT result functions (MDEV-12852, MDEV-12853, MDEV-12869)
This is a joint patch for:
MDEV-12852 Out-of-range errors when CAST(1-2 AS UNSIGNED
MDEV-12853 Out-of-range errors when CAST('-1' AS UNSIGNED
MDEV-12869 Wrong metadata for integer additive and multiplicative operators

1. Fixing all Item_func_numhybrid descendants to set the precise
   data type handler (type_handler_long or type_handler_longlong)
   at fix_fields() time. This fixes MDEV-12869.

2. Fixing Item_func_unsigned_typecast to set the precise data type handler
   at fix_fields() time. This fixes MDEV-12852 and MDEV-12853.
   This is done by:
   - fixing Type_handler::Item_func_unsigned_fix_length_and_dec()
     and Type_handler_string_result::Item_func_unsigned_fix_length_and_dec()
     to properly detect situations when a negative epxression is converted
     to UNSIGNED. In this case, length of the result is now always set to
     MAX_BIGINT_WIDTH without trying to use args[0]->max_length, as very
     short arguments can produce very long result in such conversion:
        CAST(-1 AS UNSIGNED) -> 18446744073709551614
   - adding a new virtual method "longlong Item::val_int_max() const",
     to preserve the old behavior for expressions like this:
        CAST(1 AS UNSIGNED)
     to stay under the INT data type (instead of BIGINT) for small
     positive integer literals. Using Item::unsigned_flag would not help,
     because Item_int does not set unsigned_flag to "true" for positive
     numbers.

3. Adding helper methods:
  * Item::type_handler_long_or_longlong()
  * Type_handler::type_handler_long_or_longlong()
  and reusing them in a few places, to reduce code duplication.

4. Making reorganation in create_tmp_field() and
   create_field_for_create_select() for Item_hybrid_func and descendants,
   to reduce duplicate code. They all now have a similar behavior in
   respect of creating fields. Only Item_func_user_var descendants have
   a different behavior. So moving the default behvior to Item_hybrid_func,
   and overriding behavior on Item_func_user_var level.
2017-05-23 12:45:47 +04:00
Alexander Barkov
9b79888df8 MDEV-12866 Out-of-range error with CREATE..SELECT..TO_SECONDS(NOW()) 2017-05-22 17:13:15 +04:00
Alexander Barkov
8c479820da MDEV-12856 Wrong .. metadata for DIV + MDEV-12857..errors on CREATE..SELECT..DIV
This is a joint patch for:

MDEV-12856 Wrong result set metadata for DIV
MDEV-12857 Out-of-range errors on CREATE..SELECT 2222222222 DIV 1
2017-05-21 09:28:12 +04:00
Alexander Barkov
a8caa8e04a MDEV-12854 Synchronize CREATE..SELECT data type and result set metadata data type for INT functions 2017-05-20 16:29:11 +04:00
Alexander Barkov
da63db1e3b MDEV-12719 Determine Item::result_type() from Item::type_handler() 2017-05-07 19:29:23 +04:00
Alexander Barkov
4e9022b48b MDEV-12718 Determine Item::cmp_type() from Item::type_handler() 2017-05-07 09:12:54 +04:00
Alexander Barkov
c898de84b7 MDEV-12714 Determine Item::field_type() from Item::type_handler() 2017-05-06 20:44:05 +04:00
Alexander Barkov
46239f29c6 MDEV-12713 Define virtual type_handler() for all Item classes 2017-05-06 19:12:59 +04:00
Alexander Barkov
791374354c MDEV-9217 Split Item::tmp_table_field_from_field_type() into virtual methods in Type_handler
- Adding Type_handler::make_table_field() and moving pieces of the code
  from Item::tmp_table_field_from_field_type() to virtual implementations
  for various type handlers.

- Adding a new Type_all_attributes, to access to Item's extended
  attributes, such as decimal_precision() and geometry_type().

- Adding a new class Record_addr, to pass record related information
  to Type_handler methods (ptr, null_ptr and null_bit) as a single structure.
  Note, later it will possibly be extended for BIT-alike field purposes,
  by adding new members (bit_ptr_arg, bit_ofs_arg).

- Moving the code from Field_new_decimal::create_from_item()
  to Type_handler_newdecimal::make_table_field().

- Removing Field_new_decimal() and Field_geom() helper constructor
  variants that were used for temporary field creation.

- Adding Item_field::type_handler(), Field::type_handler() and
  Field_blob::type_handler() to return correct type handlers for
  blob variants, according to Field_blob::packlength.

- Adding Type_handler_blob_common, as a common parent for
  Type_handler_tiny_blob, Type_handler_blob, Type_handler_medium_blob
  and Type_handler_long_blob.

- Implementing Type_handler_blob_common::Item_hybrid_func_fix_attributes().

  It's needed for cases when TEXT variants of different character sets are mixed
  in LEAST, GREATEST, CASE and its abreviations (IF, IFNULL, COALESCE), e.g.:
      CREATE TABLE t1 (
        a TINYTEXT CHARACTER SET latin1,
        b TINYTEXT CHARACTER SET utf8
      );
      CREATE TABLE t2 AS SELECT COALESCE(a,b) FROM t1;
  Type handler aggregation returns TINYTEXT as a common data type
  for the two columns. But as conversion from latin1 to utf8
  happens for "a", the maximum possible length of "a" grows from 255 to 255*3.
  Type_handler_blob_common::Item_hybrid_func_fix_attributes() makes sure
  to update the blob type handler according to max_length.

- Adding Type_handler::blob_type_handler(uint max_octet_length).

- Adding a few m_type_aggregator_for_result.add() pairs, because
  now Item_xxx::type_handler() can return pointers to type_handler_tiny_blob,
  type_handler_blob, type_handler_medium_blob, type_handler_long_blob.
  Before the patch only type_handler_blob was possible result of type_handler().

- Making type_handler_tiny_blob, type_handler_blob, type_handler_medium_blob,
  type_handler_long_blob public.

- Removing the condition in Item_sum_avg::create_tmp_field()
  checking Item_sum_avg::result_type() against DECIMAL_RESULT.
  Now both REAL_RESULT and DECIMAL_RESULT are symmetrically handled
  by tmp_table_field_from_field_type().

- Removing Item_geometry_func::create_field_for_create_select(),
  as the inherited version perfectly works.

- Fixing Item_func_as_wkb::field_type() to return MYSQL_TYPE_LONG_BLOB
  rather than MYSQL_TYPE_BLOB. It's needed to make sure that
  tmp_table_field_from_field_type() creates a LONGBLOB field for AsWKB().

- Fixing Item_func_as_wkt::fix_length_and_dec() to set max_length to
  UINT32_MAX rather than MAX_BLOB_WIDTH, to make sure that
  tmp_table_field_from_field_type() creates a LONGTEXT field for AsWKT().

- Removing Item_func_set_user_var::create_field_for_create_select(),
  as the inherited version works fine.

- Adding Item_func_get_user_var::create_field_for_create_select() to
  make sure that "CREATE TABLE t1 AS SELECT @string_user variable"
  always creates a field of LONGTEXT/LONGBLOB type.

- Item_func_ifnull::create_field_for_create_select()
  behavior has changed. Before the patch it passed set_blob_packflag=false,
  which meant to create LONGBLOB for all blob variants.
  Now it takes into account max_length, which gives better column
  data types for:
    CREATE TABLE t2 AS SELECT IFNULL(blob_column1, blob_column2) FROM t1;

- Fixing Item_func_nullif::fix_length_and_dec() to use
  set_handler(args[2]->type_handler()) instead of
  set_handler_by_field_type(args[2]->field_type()).
  This is needed to distinguish between BLOB variants.

- Implementing Item_blob::type_handler(), to make sure to create
  proper BLOB field variant, according to max_length, for queries like:
    CREATE TABLE t1 AS
      SELECT some_blob_field FROM INFORMATION_SCHEMA.SOME_TABLE;

- Fixing Item_field::real_type_handler() to make sure that
  the code aggregating fields for UNION gets a proper BLOB
  variant type handler from fields.

- Adding a special code into Item_type_holder::make_field_by_type(),
  to make sure that after aggregating field types it also properly
  takes into account max_length when mixing TEXT variants of different
  character sets and chooses a proper TEXT variant:
      CREATE TABLE t1 (
        a TINYTEXT CHARACTER SET latin1,
        b TINYTEXT CHARACTER SET utf8
      );
      CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;

- Adding tests, for better coverage of IFNULL, NULLIF, UNION.

- The fact that tmp_table_field_from_field_type() now takes
  into account BLOB variants (instead of always creating LONGBLOB),
  tests results for WEIGHT_STRING() and NULLIF() and UNION
  have become more precise.
2017-04-24 12:09:25 +04:00
Alexander Barkov
ba670edfa3 MDEV-12559 Split Item::temporal_precision() into virtual methods in Type_handler
- Adding a new virtual method Type_handler::Item_time_precision()
- Adding a new virtual method Type_handler::Item_datetime_precision()
- Removing Item::temporal_precision() and adding Item::time_precision()
  and Item::datetime_precision() instead.
- Moving Item_func_convert_tz::fix_length_and_dec() from item_timefunc.cc
  to item_timefunc.h. It's only two lines, and we're changing it anyway.
- Removing Item_temporal_typecast::fix_length_and_dec_generic(),
  moving this code to
  Type_handler::Item_{date|time|datetime}_typecast_fix_length_and_dec().
  This allows to get rid of one more field_type() call.
  Also, in the old reduction, Item_date_typecast::fix_length_and_dec()
  unnecessarily called args[0]->temporal_precision(). The new reduction
  does not call args[0]->datetime_precision(), as DATE does not
  have fractional digits.
2017-04-22 21:59:00 +04:00